The cloister is both a sign and a means of our radical separation from the world for the sake of offering ourselves more fully to God. Cloistered nuns are “a sign of the exclusive union of the Church as Bride with her Lord, whom she loves above all things “(Verbi Sponsa, n 4). All Christians are  called to follow Christ, and to be sacrificed with Him in some way according to their particular vocation. What characterizes the cloistered nun is that she withdraws from the world to give her whole life as fully as possible to this following of Him and participation in His sacrifice, without the addition of an external apostolate outside the monastery. She leaves her cloister only in cases of necessity (such as doctor visits) and does not make home visits. Her separation from the world is a concrete and visible one, marked by the delineation of the enclosure (the area of the monastery property reserved exclusively for the nuns) and the lattice-work grille between the nuns and guests in the chapel and guest parlor. This voluntary separation enables her to make a continual, ceaseless offering, as she spends herself in worship of God day and night. She is freed from worldly business and distractions which would pull her away, if only temporarily, from her work of praising God. She finds that, more and more, she loves and longs for the cloister, this lonely place which gives her space to belong wholly to the Beloved. Without real distance from the noise and bustle of the world, her heart could not be formed in a constant vigilance which keeps watch for the Lord and desires Him to do with her freely whatever He wills. The cloister ensures both the totality and the permanence of her offering. 

Far from cutting the nun off from the world, the cloister allows her to be “united with the rest of mankind in a more profound sense in the heart of Christ” and to sustain the missionary activity of the Church through her prayers (Venite seorsum, III). We enter the cloister to give our lives in worship to God, simply because He deserves it, and Our Lord makes this offering, united with His own self-offering on the Cross, fruitful for the Church and for souls.